At the beginning of your upkeep, create a colorless artifact token named Land Mine with ", Sacrifice this artifact: This artifact deals 2 damage to target attacking creature without flying." Then flip a coin. If you lose the flip, Goblin Kaboomist deals 2 damage to itself.

Choose any number of target players. For each of those players, reveal cards from the top of your library until you reveal a nonland card, Kaboom deals damage equal to that card's converted mana cost to that player, then you put the revealed cards on the bottom of your library in any order.